The association between body mass index and distribution intensity of tumor treating fields (TTFields) in the lungs.

Abstract

e20559 Background: Tumor Treating Fields (TTFields) therapy is a first-in-class locoregional and noninvasive cancer treatment modality. TTFields are electric fields that disrupt processes necessary for cancer cell viability and tumor progression. A portable medical device generates TTFields, which are delivered noninvasively to the tumor area via 2 pairs of transducer arrays placed on the skin. TTFields therapy is currently approved for recurrent and newly diagnosed glioblastoma and pleural mesothelioma, with studies underway in other solid tumor types, including non-small cell lung cancer (NSCLC). Preclinical studies have shown that the effectiveness of TTFields depends on several factors, including field intensity. Given that 1 in 3 adults is overweight or obese, it is relevant to determine the effect of body mass index (BMI) on TTFields intensity to the lungs. Simulation-based methods were utilized, with the hypothesis that TTFields could be delivered to regions of interest (ROI) at therapeutic field intensities of > 1 V/cm, irrespective of BMI. Methods: Female computer phantom models with BMIs of 22 (healthy), 26 (overweight), and 30 (obese) were used to simulate TTFields intensity using small (13 disk) and large (20 disk) arrays placed on the thoracic region. The distribution of TTFields in each model was then determined using a computer-generated electric field intensity map. Field intensity values across the entire lungs were analyzed and compared. Results: When TTFields were delivered with large arrays, field intensities were clinically meaningful ( > 1 V/cm) in all lobes of the lungs for all BMI models. When TTFields were delivered with small arrays, meaningful levels of field intensity were achieved in all lung lobes, except for the BMI 30 model, where field intensities were slightly lower than 1 V/cm in the right middle lobe. Conclusions: These results show that TTFields can be delivered at therapeutic field intensities in patients with a BMI up to 30, providing the appropriate TTFields array size is used. Results from this simulation-based study support current clinical studies of TTFields therapy in lung cancer, (LUNAR, NCT02973789) and underscore the importance of appropriate array size selection. Additionally, these results may provide guidance for using TTFields therapy to treat a broad population of patients with lung tumors.